Method of repairing cracked or broken structures by welding



Sept 22, 1925. msam R. MATTICE METHOD OF REPAIRING CRACKED OR BROKEN STRUCTURES BY WELDING Or ginal Filed Oct. 5,, 1924 gnvm Lfoz Patented Sept. 22, 1925.

UNITED STATES ROYAL MATTICE, OF BETHLEHEM, IPENNSYLVANIA.

METHOD OF REPAIRING CRACKED OR BROKEN STRUCTURES BY WELDING.

original application filed October 3, 1924, Serial No. 741,494. Divided and this application filed December 24, 1924. Serial No. 757,841.

To all whom it may concern:

Be it known that I, ROYAL IWATTICE, citizen'of the United States, residing at Bethlehem, in the county of Northampton and 6 State of Pennsylvania, have invented certain new and useful Improvements in Methods of Repairing Cracked or Broken Structures by-VVelding, of-which the following is a specification.

This invention relates to the method of repairing cracked or broken structures by welding and has particular reference to the repair of double-walled structures which are spaced from each other by webs, braces or 15 the like. This application is a'division of my copending application, method of repairing cracked or broken structures by electric welding filed October 3, 1924, Ser. No. 741,494.

Vfhile this invention has been practiced specifically in the repair of cracked or broken tops of hot blast stoves and the drawings show generally such a structure, it is obvious that the hereindisclosed method 55 is adaptable for the repair of any doublewalled structure, and I desire it understood that this invention is not restricted solely to the repair of hot blast stove tops and wherever mention is made of stove tops it is merely by wayof example.

Metallic structures which are subjected to heat will crack from continual expansion and contraction and particularly is this true of hot blast stoves. Heretofore attempts have been made to repair the cracked structn 5 by acetylene welding but it has been found that if the old crack did not reappear in the structure new cracks appeared adjacent the weld. Fire clay has been resorted 3 fill up the crack and a plate then clamped over the repaired surface by screws or the like' lhis method has proved unsatisfactory in practice.

In the case of hot blast stove tops, the

i type illustrated being doubled-walled, the upper and lower walls are separated by Webs and braces and it has been found in ractice that cracks appear adjacent the we and adjacent the brace.

It is one object of the present invention to provide a method for repairing the cracked stove tops when the same are cracked adjrcent the web or brace.

It is a further object of the invention to provide a method forthe repair of cracked double walled structures.

It is a still further object of this invention to providea method for repairing cracked or broken hot blast stove tops.

Another object of this invention to provide a method of repairing cracked or broken double-walled structures such as hot blast stove tops or the like by electric welding.

Other objects and advantages of this invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a sectional view of a hot blast stove top.

Fig. 2 is a fragmentary front elevation, partly in section, of a repaired portion of a stove top.

Fig. 3 is a perspective view of a portion of a stove top disclosing one of the steps in the method of repair.

Fig. 4: is a perspective view of a portion of a stove top showing a web and brace forming a part thereof, the same having been repaired.

Referring now more particularly to the drawings, A designates a hot blast stove top in its entirety, the same comprising an upper section 1, a lower section 2 and a stack 8 the latter secured to section 1 by bolts 4 or the like.

The upper and lower sections 1 and 2 are spaced from each other a distance of approximately three inches, in stoves of present day usage, and the upper section 1 is supported by means of a plurality of webs 5, each provided with a brace 6. It is to ht understood of course that both the sections 1 and 2 are provided with a central opening commun cating with the stack 3 and that braces 6 are substantially arcuate in shape and are spaced each from the other circumferentially around the opening.

It has been found that due to expansion and contraction the upper sections 1 and 2 crack and also that braces 6 and webs 5 often crack.

The cracks above mentioned are designated at 7, indicating the crackspn a brace.

In repairing a cracked brace, a portion 10 of section 1 is removed just abo e the web, (see Figures 3 and 4:} ti iosing the web 5. The brace 6 the; ed by any greater accuracy suitable method, for example, oxyacetylene.

I then provide an entirely new brace in two sections 11 and 12 respectively (see Figure 3), one edge of each section being tapered as shown at 13. The new brace is placed. in position against the web 5 with the tapered edges facing each other but providing a space therebetween. As shown in Figure 3 the two sections 10 and 11 are placed in contact with the forward edge of the web 5 and when the elements are assembled as just described the sections 10 and 11 are then welded to the web 5, the finished article being shown more clearly in Figure 4 in which Figure 14rshows the weld, The portion 10 is then replaced and welded to the newly formed brace and to the web 5 thus forming an inte ral structure and ef-= footing a complete repair of the previously cracked structure.

lit often happens that the stove top is cracked adiacent the web 5 as well as the brace G and also the web 5, due to excessive expansion and contraction, also cracks In either of these events, a portion of section 1 above the web is removed and. the web and brace both removed An opening is formed in section 91 and the edges of said opening are tapered shown at 15 A- pad is then held against the lower face of section 2 covering the t will Hg formed therein, and a new web l/Z supported. in the opening; on the pad With. the new web in position I tleu. weld shown at lfs, thus unit-in the section 9;, p 1.6 and. we; A new brace then T lded to the web 19' sections 1'. and i. a mann 1 hereinbe fore desorib d r 4 PT,

i then. as the step in. the repair oi; the structure by this n.1,1l the opening in section 1 also e the W v. clued as shown. at 21., ll sufiicicnt met. has been removed from. above the "web to ermit the replace ment oi the m t l itsel", such metal we ed back into p N 1 tion Li, hows er in the rope oi the structure inst described it is usually necessary to r -.ncve or y small amount cit metal in section 1 in l in this event no new piece or: in col ncccv be welded to section. i. it being on y necessary to fill up the opening by metal by welding lit has been found more practical. to carry out the method described by electric welding the degree of heat necessary to efifect a practical weld can be controlled with than can heat of any other welding process and a iar more efiicient weld is thus obtained From the above description it is believed that the method will be obvious to those skilled in the art but I desire it understood that the drawings are merely by way of me ample and that the herein described method of repair is applicable generally to any metallic double-walled structure in which the walls are separated by means of braces or webs or both. It is further to be understood that various changes may be made within the scope of the appended claims Without departing from the spirit of the invention.

What I claim as my invention and desire to secure by Letters Patent is:

1. The method of repairing cracked. or broken. stove top braces which comprises removing a portion of the upper wall of the stove top, removing the cracked or broken brace, placing a new brace in position and welding the same to said stove top, replacing the portion previously removed. from the upper wall, and finally welding said portion. to said upper wall and to said brace In a stove top having double walls webs and braces separating and suppc the same, the method of repairing or or broken braces which comprises, remm.v a portion. of the upper wall; above t 1 cracked or broken brace, removing the cracked or broken brace, forming a new brace in two sections, welding said sections to said lower wall and said web to form unitary structure of said brace, lower and said web, and. finally welding tl'ic portion previously removed from said. u wall back in position in said upper wall. to said web and brace= 3. in a stove top having double w'a webs and braces separating and supper the smile, the method of repairing; or or broken webs and braces whicl' removing a portion oi the upper the cracked or broken web and brac moving the cracked or broken brace, re ing the cracked or broken web, forming opening; in the lower wall, securing; a against the lower face oi' the lower it positioning a new web between the up, and lower walls, with the lower edge therco in said openiinn-welding said web to 1; lower wall and to said pad, forming a brace and positioning the same against sznc, web, welding said brace to said web and. lower wall, and finally welding the portion previously removed from said upper wall back in position in said upper wall and to said web and brace.

In testimony whereof I afliz; my Slgllfillllii'fi ROYAL MATTlClLL 

